Field of the Invention
The invention relates to a flat or sheet-like construction such as a metal foil and to a honeycomb body.
European Patent No. EP-0 454 712 B1, which corresponds to U.S. Pat. No. 5,157,010, describes a flat or sheet-like construction which is formed from a metal sheet or foil. The flat construction has at least two structures which are spaced from a reference surface and which superpose one another at least partially. The mutually superposed structures are in the form of grooves or channels. The structures are of different dimensions. Some of the structures form so-called macrostructures and some of the structures form so-called microstructures. The microstructures overlap the macrostructures. European Patent No. EP-0 454 712 B1 also discloses a honeycomb body having a plurality of passages or channels through which a fluid can flow in a flow direction. The honeycomb body is formed from at least one flat or sheet-like configuration. The passages are defined by the structuring of the flat or sheet-like configuration.
A further configuration of a flat or sheet-like construction which is particularly suitable for forming a honeycomb body is known from International Publication No. WO 96/09892, which corresponds to U.S. Pat. No. 5,795,658. The flat construction has structures which are partially mutually superposed. This flat construction also has macrostructures and microstructures. The microstructures extend at an angle relative to the macrostructures. It can also be seen from International Publication No. WO 96/09892 that the microstructures also cross each other. In particular the microstructures cross at the crests of the macrostructures. The flat construction disclosed in International Publication No. WO 96/09892 is made of a metal sheet or foil in which the structures are formed.
Particularly in the region of the partially overlapping structures which are formed for example by the points of intersection of the microstructures, there are problem zones which result in a heavy loading of the material forming the flat construction, during a procedure for shaping the material.
Due to the deformation characteristics of the metal foil or sheet, it is not possible to guarantee that, in the region of the mutually superposed structures, the transition between the mutually superposed structures is satisfactorily produced. That has an effect in particular on structures which are of relatively large dimensions.
International Publication No. WO 96/09892 also describes a metal honeycomb body having a plurality of passages or channels through which a fluid can flow in a flow direction. The passages are formed of metal foils or sheets which are at least partially provided with at least one macrostructure which defines the passages and which determines the honeycomb form of the metal honeycomb body. A part of the sheet metal portions has at least in partial regions additional microstructures. The microstructures extend at an angle to the flow direction, successive microstructures are spaced from one another, and the microstructures cross each other.
German Patent No. DE 38 44 350 C2 discloses a flat construction which has structures. The structures are limb-shaped or bar-shaped portions which are pressed in a bridge-like shape out of a plane of the flat construction. The limb-shaped or bar-shaped portions are provided side-by-side in longitudinally directed zones extending in mutually parallel relationship. The limb-shaped or bar-shaped portions project towards both sides out of the plane of the metal foil or sheet. The limb-shaped or bar-shaped portions which project on both sides are produced by a procedure in which an initially flat smooth metal strip is passed through a pair of embossing-cutting rollers by which the strip is partially slit and the limb-shaped or bar-shaped portions are pressed out towards both sides of the plane of the strip. A flat construction of that kind has no overlapping structures.